schneider



UNITED STATES PATENT OFFICE.

JAMES H. ROGERS AND CHRISTIAN G. SCHNEIDER, OF WASHINGTON, D. C., ASSIGNORS TO HAYWARD M. HUTCHINSON, OF SAME PLACE.

TELEPHONE.`

SPECIFICATION forming part of Letters Patent No. 251,466, dated December 27, 1881.

Application tiled June 14,1881. (No model.)

To all whom it may concern:

Be it known that we, JAMES HARRIS Roe- ERs and CHRISTIAN G. SCHNEIDER, citizens ofthe United States, both residing at Washin'gton,in the county of Washington and District of Columbia, have invented Improvements in Telephones, of which the following is a specification.

Our invention relates to telephones in which ro audible signals are transmitted by sound- Waves in gas contained in the pipes of a building, said gas being confined and prevented from escaping by iiexiblediaphragms, th rough which the sounds are transmitted and received. The qualities necessary in a membrane for this purpose are entire im perviousness to gas, great fiexibility, adapting it to respond with freedom and delicacy to the sound-waves, and sufficient strength and durability. A metallic diazo phragm is not sufficiently sensitive to yield the best results, a diaphragm of rubber is too perishable, and We have not found any other manufactured material that is absolutely impervious to gas. By experiment we have found that the entrails of animals furnish the best material for the purpose. We prefer to use the intestines of hogs; but bladder is found to answer well. It will be apparent that diaphragms thus made are liable to injury by 3o punctuiing with any sharp instrument. We have therefore dtvlsed and have combined with the aforesaid iiexihle diaphragm a metallic shield permitting the passage of sound-waves around it, While preventing approach to the diaphragm of any hard body. As a further means of preventing any possible escape of gas, we mount the transmittin g and receiving diaphragms in pipes jointed to the main gaspipe, and furnished at the joint with a stopcock or valve so arranged that when the transmitting or receiving instrument is drawn forward for application to the mouth or ear of the user the gas-connection will be automatically opened, and when the said instrument is replaced the connection will be shut off, so that the membrane may not be exposed to the pressure of the gas when the telephone is not in use.

In the accompanying drawings, Figure l is a diagram, partly in section, of a telephonie apparatus illustrating our invention. Fig. 2 is a section, on a larger scale, of the transmitting or receiving instrument, or an instrument which may be used alternately for each purpose. Fig. 3 is a horizontal section on the line 3 3, Fig. 1. Fig. 4 is avertical section on the 55 line 4 4, Fig. 3. Fig. 5 is a section showing a sliding instead of a turning valve.

A represents the transmitting or receivingv diaphragm, formed, as already stated, of entrail or bladder or like animal membrane. This 6o membrane is stretched within a mouth or ear piece,B, of any suitable shape, which m ayseve the purposes both of a transmitting and of a receiving instrument, asimilar instrument being placed ateach Iend ot' the telephone sys- 65 tem, as shown at B `B.

C is the main conducting-pipe, which may constitute'the ordinary gas-pipe of a building.

Our mode of transmitting telephonie signals by sound-waves through gas coi'iiinedwithin 7o pipes, as stated, necessitates having the gas in contact with the inner surface of the transmitting and receiving diaphragm, and we have, as already stated, found the best effects produced by using for this purpose animal membranes, which, though sufficiently strong and tenacious and impervious to perfectly confine the gas so long as they remain intact, are neverf theless liable to injury by puncturing or cutting, either by carelessness, accident, or design. 8o We therefore tix a metallic shield, D, in front of the membrane, so as to prevent the approach ofany object which might injure it. It is manifestly undesirable to have the membranes depended on to confine the gas while not in use l for talking. We therefore provided our gastelephone with a device by which the act of raisingor drawingouttheinstrumentfor speaking or hearing Will open communication between the gas'within the pipes C and the inner 9o surface of the transmitting or receiving membrane A, and the dropping of the instrument will close such communication. To this end we employ a movable pipe, H, to one end of which the instrument A B is connected, while the other end of said pipe is attached to a cock' or valve, I, adapted to open the connection between the pipes H and C by the act of raising the pipe H or sliding it into position for use, and to close such communication `by the actof Ioo restoring the said pipe.

ln order to provide a call-signal which will f be in constant readiness for the use of a speaker at a distant point, and will not be shut oftl from communication with the interior of the gas-pipe when not in use, we employ a call-signal such as we have described and claimed in another application, consisting ot'a metallic diaphragmmembrane, E, adapted to coniinethe gas within the pipes and not liable to beinjured by puncturing said membrane, being in contact with the hammer F ofthe bell Gr, so as to strike the said bell by the Vibration imparted by the sound-waves within the pipes.

Fig. 5 shows the pipeH opened to the gaspipe by slidin g it in, and when released thrown out by a spring, h, to close it; but it is manifest that it may be arranged to open by being drawn out, it' preferred.

W W represent the walls of two apartments in which the respective ends or stations ot` the apparatus are located, the apparatus being extended to as many such apartments as desired.

We are aware that diaphragms of animal membrane have long been used in telephones -of other kinds; but such membrane possesses peculiar value and adaptability in a gas-telephone because of its perfect impermeability and its great ilexibility; but, as it is inexpedient to have an animal membrane constantly exposed to thc pressure of gas, the merit ot' this part of our invention `consists in the combina tion, in a gas-telephone, of a diaphragm of animal membrane to conine the gas while permitting the passage of sound-waves, and a valve by which the gas-pressure maybe shut oft' from the diaphragm when not in use.

Having thus described our invention, the following is what we claim as new therein and desire to secure by Letters Patent:

1. In a gas-telephone, the combination ot' a transmitting or receiving diaphragm and a valve or cock by which the gas within the tubes may be shut oft' from said diaphragm when the telephone is not in use for talking.

2. In an apparatus for conveying telephonie sounds or signals through gas or other pipes, thc combination ot' a transmitting and receiving instrument, a movable pipe connecting said instrument with the fixed or main gas-pipe, and a cock or valve at the connection between said movable and fixed pipes, adapted to be opened by moving the instrument into position for use and closed by the replacingof thcsaine, substantially as described.

3. In combination with the diaphragm A, the shield D, applied substantially as herein described, to permitthe passage of soundwaves around it while protecting the said diaphragm A from injury.

J. H. ROGERS. CHRISTIAN Gr. SCHNEIDER.

Witnesses:

Ooravlns KNIGHT, HARRY E. KNiGH'r. 

